This species is known only from one site near Santo Tomás Tecpan, in the Sierra Madre del Sur de Oaxaca, south-eastern Oaxaca, Mexico, at 2,458m asl.
Habitat and Ecology
It lives terrestrially in pine-oak forest. It presumably reproduces by direct development.
Observed only twice in 60 years. Recently rediscovered (two specimens found at the type locality in 2001); this species is extremely rare, and very few specimens are known (Hanken and Wake pers. comm. 2007).
The forests where it is found have been severely altered as a result of logging, agriculture, and human settlement, and very little good habitat remains.
Habitat protection is the most urgently needed conservation action for this species, since it is not known from any protected areas. It is protected by Mexican law under the "Special Protection" category (Pr).
Red List Status
Critically Endangered (CR)
The name Thorius minutissimus has been applied to populations at other localities, but these are now known to belong to other species in the genus (Hanken and Wake pers. comm.).
Gabriela Parra-Olea, David Wake, James Hanken 2008. Thorius minutissimus. In: IUCN 2014